Sand muller



Dec. 23, 1941. w. BAXTER 2,267,577

' SAND MULLER Filed Nov. 24, 1939 3 Sheets-Sheet 1 W. BAXTE R Dec. 23,1941.

SAND MULLER Filed Nov. 24, 1939 5 Sheets-Sheet 2 Dec. 23, 1941. w.BAXTER 2,267,677

SAND MULLER Filed Nov. 24, 1939 3 Sheets-Sheet 5 Patented Dec. 23, 1941-SAND MULLER- William Baxter, Montreal, Quebec, Canada, as-

signor to Crane 00., Chicago, 111., a corporation of IllinoisApplication November 24. 1939, Serial No. 305,884

. 2 Claims.

This invention relates to a foundry sand muller having especially forits functionthe preparation or reconditioning of molding sand. .Moreparticularly, the invention relates to a continuously operating type ofsand muller as distinguished from those generallyreferred to as batchtype mullers.

One of the more important advantages of the present invention lies inthe provision of an apparatus in which one roller or ironer completelymulls or prepares a mixture of sand, clay and bond while the saidmixture is making a single pass or contact thereunder.

Another object lies in the provision of an apparatus which willcontinuously and efficiently mull or prepare foundry sand for molding asthe said sand is fed to the muller regardless of wide variations in thequantity of sand supplied to the muller for preparation.

A still further object of the invention is to provide a sand mullerwhich utilizes a new type of mulling action, not heretofore available,for the -more efiicient treatment of the sand and clay particles wherebythe clay is more evenly and thoroughly distributed in the sand. Ashereinafter described in greater detail, the increased efiiciency of mymulling apparatus is derived from a novel brushing, crushing and tearingaction imparted to the sand preferably by a specially constructed rolleror ironer having a peripheral velocity which is not the same as thevelocity of the'sand being fed to the said roller by a conveyor.

It is also a further object of my invention to provide a molding sandmuller which is readily adaptable to being installed in existing sandreconditioning or transporting systems and which when installed requiresa relatively small amount of power for its operation.

Other objects and advantages of my present invention will becomeapparent upon proceeding with the following detailed description of 'apreferred embodiment of the muller illustrated by the accompanyingdrawings in which:

Fig. 1 is a side view of the complete sand preparing unit.

Fig. 2 is a plan view thereof.

Fig. 3 is a fragmentary end view showing the preferred relativepositioning of the respective sand tempering belt, the mixerv and thecooling belt. 1

Fig. 4 is a magnified fragmentary plan view showing in detail themounting of the roller or ironer above the tempering conveyor belt.

Fig. 5 is'a side view thereof.

Fig. 6 is a sectional view showing the preferred construction of theroller or ironer.

Like reference numerals refer to like parts throughout the various viewsof the drawings.

Referring to Fig. 1, the preferred and conventional type of foundrymolding sand conditioning apparatus to which I adapt my sand mullercomprises a rotary screen or riddle I covered by an open endedbottomless housing 2 both of which are positioned immediately above aportion of an endless'belt type conveyor or tempering belt 3. The saidtempering belt extends horizontally from one end of the riddle and has aplurality of stationary sweepers 4 (more clearly shown in Fig. 2)superposed upon a central portion of the belt. At the extreme end of thetempering belt I place an independently driven roller or ironer 5 theconstruction of which will hereinafter be described in greater detail.Immediately below the extreme end of the tempering belt I place theinlet of a conventional mixer or beater 6 (more clearly shown in Fig. 3)which may comprise an enclosed rotatable worm screw or, if desired, mayincorporate any other means for mixing or beating and advancing materialwithin the mixer to the opposite side or outlet end 1 thereof.Adjacently below the outlet of the mixer 6, .I prefer to provide aconveyor or cooling and transporting belt 8.

The manner of operation of the hereinabove briefly described apparatuscomprises supplying the riddle or screen I with used and/or new moldingsand by any convenient means .(not shown) such as a hopper or a conveyorbelt having a chute to direct the sand into the riddle.

The riddle, previously described as being rotary,

falls upon the tempering belt 3.

The belt 3 encircles a pair of journaled rollers l8 and. I9 and has aplurality of supporting rollers 2| which prevent undesirable sagging ofthe con-- veyor belt. The roller l8 has a belt tension adjusting bearing22 and the roller l9 has attached to its axle 23 a pulley 24 which bymeans of the belt 25 is driven by the pulley 26 secured upon thedriveshaftz'l. The rotational drive imparted to the pullley I9 ispreferably clockwise whereupon the uppermost portion of the belt 3 willtravel in the direction indicated by the arrows. Thus, sand falling uponthe tempering belt from v the riddle moves with the belt past thesweepers 4 which thus effect an even distribution of the sand upon thebelt.

Referring now to Figs. 4 and 5, the sand, after being swept to an eventhickness across the width of the belt 3, approaches the independentlydriven roller or ironer 5 wherein lies the essence of my invention. Theironer 5 is rotatably mounted upon a pivotable framework 28- comprisinga pair of arms loosely attached to thecountershaft 29, the latter beingsupported above the tempering belt by the'bearing brackets .3! and thestationary framework 32. The outermost end of the pivotable framework 28carries a scraper 33, preferably, made of rubber, leather, or the likematerial, which extends the length of the ironer 5. A pair of adjustablestops 34 extend upwardly from the general framework 13 and abutthepivotable ironer-carrying framework 28, maintaining the latter in itslowered position so that the ironer will not come in direct contact withthe belt 3. It has been found desirable to make the stops 34 adjustableso as to maintain the periphery of the ironer 5 pref erably about A-inchabove the tempering belt, although the latter distance may be varied;

The independent drive of the ironer 5 is provided for respectively bythe pulley 35 upon the shaft 23, the crossed belt 36, the pulley 31secured to the countershaft 29, the pulley 38 also secured'to thecountershaft 29, the belt 39 and the pulley 4|, the latter being securedto the journ'aled shaft 42 of the ironer 5. Thus it can readily beobserved thatvupon proper selection of the ratio between the diametersof the pulleys 35 and 31 the peripheral velocity of the ironer 5 may beadjusted to anydesired speed and that the direction of rotation of theironer will be counterclockwise. The apparatus has been found duringactual operation to give satisfactory results in the mulling of sandwhen the lineal velocity of the tempering belt 3 is about 212 feet perminute and the peripheral velocity of the ironer 5-is about 230 feet perminute.

In operation, the sand upon the tempering belt after being swept to aneven thickness by the sweepers 4 is fed under the ironer 5 the lowersurface of which, by reason of its counterclockwise movement, istraveling in the same direction as the sand but preferably at a greatervelocity than the sand, whereupon the sand receives a novel brushing,crushing and tearing action which separates and intermingles the variousparticles constituting the sand mixture. Re-

silience in the action of the ironer is provided for ing belt 3 or elseis scraped therefrom by the scraper'52. -The scraper 52 is preferablysupported by the extensions 53 secured to the general framework l3 andcomprises a toggle construction mounted upon the journaled shaft 54which extends through the bearings 55 and 56.

A weighted lever 51 securedto one end of the shaft 54 is provided tomaintain the scraper blade 58 normally against the tempering belttoremove any particles or wads of sand adhering to the belt. Satisfactorymaterial for use. as a scraper blade 58 is hardwood; however, ifdesired, other materials may be used.

As more clearly shown in Figs. 1, 2 and 3, the sand after leaving thetempering belt 3 drops into a conventional mixer or heater 6,aspreviously explained, and, as it is advanced toward the outlet 1thereof, receives a thorough mixing,

beating and fiufiing treatment which suitably prepares the sand for useby a foundryman in making molds. The mixer 6. is preferably providedwith a belt drive 59. From the mixer outlet 1 the sand needs only to betransportedto the location of its use and in the event that it. must betaken some distance from the mixer, a

satisfactory method-of transporting and incidentally cooling the sand isprovided by the belt conveyor 8 traveling around the roller GI mountedupon the bearings 62 and the framework 63.

by the tempering belt 3 which has no support ,directly beneath theironer and by the pivotability of the framework 28 which allows theironer to rise upon the occurrence of an increase in the thicknessandquantity of sand upon the temper-' ing belt. Obviously, the freeriding weight of the ironer and its framework thus assist materially inthe mulling treatment of the sand;

The construction of the roller or ironer 5, reference being had to, Fig.6, comprises preferably a hollow metallic cylinder 43 having an externalcovering of rubber or the like material 44. Heads and 46 are provided inthe ends of the cylinder for the purpose ofmaking it a liquid-tightcontainer and to provide supports for theshaft 42. The shaft 42 isjournaled in the bearings 41 and 48 and, as previously described, isdriven by the pulley 4| and the belt/39. A removable plug 49, isprovided in the head 46. for the introduction of a weighting material 5|such as water, oil or other liquidor granular substance within theironer. The amount of said weighting material may, of course, bereadilydetermined by experiment taking into consideration the size of theironer and the average condition of the sand passing under the ironer.

Attention-is again directed? to Figs. 4 and 5. The sand, after receivingthe treatment afforded by the ironer. 5, either falls from the temper-Having thus described and illustrated a preferred embodiment of mymulling apparatus, I

wish it to be clearly understood that various changes and modificationsof the construction may be made without departing from the spirit andscope of the invention as defined by the claims appended hereto.

' I claim:

1. A continuously operating type sand muller comprising screening means,a sand tempering and transporting belt encircling a pair of jour--'naled rollers, an ironer, the said ironer compris-n ing a rotatableroller, the said belt being horizontal and flexible or freely suspendedin the region of the journaled roller adiacent'the said" ironer, aflexibly mounted carrying 'member for the said rotatable rollerpositioned-adjacent one of the journaled rollers of the saidtransporting belt, thesaid rotatable roller being mounted in spacedrelation above an end flexible portion of pendently driven weightedroller mounted upon a pivotable carrying member in proximity to an endportion of the said conveyor and adjacent to one of the said pulleys,the said weighted roller being axially disposed from the said pulleys ina /direction toward the span of the said belt as defined by the spacebetween the said pair of' pulleys, whereby upon the conveyance, of sandupon the saidbelt, the spanof the latter member is depressible over asection beneath and adja-'- cent to the said weighted roller, the saidbelt being horizontal and'fiexibly or freely suspended in the region ofthe journaled roller adjacent the said ironer, the said roller having aperipheral :velocity which is not the same as thevelocity of the saidtempering conveyor belt.

